The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the inventors hereof, to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
This disclosure relates generally to signal detection, and more particularly to detecting signals received in a multiple-input multiple-output (MIMO) system by performing maximum likelihood demodulation using a soft sphere decoder.
With the continuing demand for higher-speed digital communications systems and higher-density digital storage systems, various techniques have been applied to increase the capacity of these systems. However, even with high-capacity communications and storage media, their respective bandwidths and densities are still limited. Therefore, MIMO systems are often used to fully exploit the capabilities of these systems. In particular, increasing the dimensions of these systems enables higher throughput and reliability, as more information can be conveyed without increasing the bandwidth of such systems.
However, the efficiency gained by MIMO systems comes at the expense of a complex receiver design. In particular, a MIMO receiver may obtain a plurality of signals from its multiple receiver inputs, where each signal includes information from each of the multiple transmitter outputs. From all of this jumbled information, a MIMO detector can attempt to recover the independent information transmitted from each of the various transmitter outputs. Thus, this information recovery process may require some tradeoff between receiver complexity and performance.